1. Field of the Invention
This invention pertains to large diameter fluid flow ducts for use in ocean engineering and the like. More particularly, it pertains to a pipe assembly which, if support thereof from above is lost, sinks to the ocean floor and assumes a vertical attitude which facilitates recovery of the pipe assembly.
2. Review of the Prior Art and Its Problems
Many sophisticated proposals have been made in the field of ocean engineering which call for the use of large diameter vertical ducts of great length extending from at or near the ocean surface to lower ends unconnected to the ocean floor. These proposals include concepts for ocean thermal energy conversion and for mariculture.
The ocean thermal energy conversion (OTEC) concepts propose to use the difference in thermal energy levels between warm surface water and colder deep water to generate electricity, for example. The available energy level difference is low and so these proposals rely on the use of very large quantities of warm and cold water, and call for the necessary large volumes of deep ocean cold water to be brought to the hull of the facility at the water surface through very large vertical ducts of great length.
The presence of the pipe assembly depending from the OTEC hull effectively prevents the hull from moving off its assigned location in the event of an emergency or if it is necessary to maintain or service the hull. The pipe assembly therefore should be releasably connected to the hull so that it can be jettisoned when necessary. The pipe assembly is expensive as well as large, and the problem then becomes one of what to do with a jettisoned or released pipe assembly which may have a length of 2000 feet or more. Also, in view of its cost, it is desirable that a released pipe assembly be readily recoverable for continued use.
A need is thus seen to exist for an ocean engineering cold water rise pipe assembly which is both readily releasable from a supporting structure at or adjacent the ocean surface, and which, after release, is readily recoverable for re-use.